The potential for temperature acclimatisation of reef corals in the face of climate change

Abstract

Coral bleaching has taken centre-stage in the debate over the likely biological effects of global environmental change. Central to any judgements on this issue is the ability of corals to display increased tolerance of debilitating or lethal conditions through phenotypic adaptations, such as heat-hardening, longer-term acclimatisation responses or even trans-generational epigenetic effects. But the key question is whether the magnitude of such responses can match the predicted increases in sea temperatures over the period of global warming. In the recent literature, much has been said about the potential for acclimatisation in tropical reef corals and how it may, or may not, be significant in the context of the world's changing climate (Hughes et al. 2003; Hoegh-Guldberg 2004; Donner et al. 2007; Hoegh-Guldberg et al. 2007; Maynard et al. 2008a; Donner 2009). In fact, we know remarkably little about the potential for and extent of acclimatisation in corals, and the complex physiology and behaviour underlying the phenomenon (Edmunds and Gates 2008; Maynard et al. 2008a). It is important at this stage to define the terms used in this chapter following Bligh and Johnson (1973) since there has been, and continues to be, considerable confusion in their use in the literature together with established concepts in thermal biology (see Box 1). © 2011 Springer Science+Business Media B.V.